/*
 * Copyright (c) 2016, The National Archives <pronom@nationalarchives.gov.uk>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 *  * Neither the name of the The National Archives nor the
 *    names of its contributors may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package uk.gov.nationalarchives.droid.core.interfaces.filter.expressions;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

/**
 * @author rflitcroft
 *
 */
public abstract class Junction implements Criterion {

    private static final String SPACE = " ";
    private List<Criterion> criteria = new ArrayList<Criterion>();
    private String op;
    
    /**
     * 
     * @param op the operation
     */
    protected Junction(String op) {
        this.op = op;
    }
    
    /**
     * Adds a criterion to this Junction.
     * @param criterion the criterion to add
     * @return this Junction
     */
    public Junction add(Criterion criterion) {
        criteria.add(criterion);
        return this;
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public Object[] getValues() {
        List<Object> params = new ArrayList<Object>();
        
        for (Criterion criterion : criteria) {
            params.addAll(Arrays.asList(criterion.getValues()));
        }
        
        return params.toArray();
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public String toEjbQl(QueryBuilder parent) {
        if (criteria.isEmpty()) {
            return "";
        }
        
        StringBuilder sb = new StringBuilder();
        sb.append("(");
        for (Iterator<Criterion> it = criteria.iterator(); it.hasNext();) {
            Criterion criterion = it.next();
            sb.append(criterion.toEjbQl(parent));
            if (it.hasNext()) {
                sb.append(SPACE + op + SPACE);
            }
        }
        sb.append(")");
        
        return sb.toString();
    }
}
